Abstract
The aim of this study was to assess the genetic variability among lysine-rich cultivars of sorghum (IS 21702; CVS 1365, G 1058, G205 and CVS 549) and to compare with low lysine cultivar White Martin and a chemically induced high lysine mutant P721O. The lysine-rich cultivars contain approximately 1.5 to 2 times more lysine when compared to low-lysine cultivar. Sodium-dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of kafirins showed the absence of both 25.3 kD and 25.9 kD alpha-kafirins in lysine rich cultivars IS 21702, G 1058 and CV 365 and only the 25.9 kD protein was not present in G 205 compared with a low-lysine cultivar White Martin and with a chemically induced high-lysine mutant P721O. Southern blot analysis with RsaI enzyme gave significantly different banding pattern indicating the absence of 1.0 kb band in lysine-rich cultivars IS 21702, G 1058 and CVS 365 compared to White Martin indicating genetic variability among these cultivars. The detected variability among kafirins both in SDS-PAGE and Southern blot could be effectively used as markers in selection of lysine-rich cultivars for further use in breeding programme.